CORDIS provides links to public deliverables and publications of HORIZON projects.
Links to deliverables and publications from FP7 projects, as well as links to some specific result types such as dataset and software, are dynamically retrieved from OpenAIRE .
Exploitable results
The overall objective of the project is to investigate the influence of rare earth additions on the kinetics and properties of various plasma thermochemical processes, with the aims of improving their efficiency, quality and productivity, as well as reducing energy consumption and environmental contaminants.
Three different plasma thermochemical treatment processes were under investigation; DC plasma nitriding (DCPN), active screen plasma nitriding (ASPN), and Plasma Immersion Ion Implantation (PI3) nitriding. Several methods were developed for introducing rare earth (RE) elements to the plasma-processing medium. These involved using rare earth (RE) material in gaseous, vapour and solid form.
During the first two-year period of the project, several significant improvements in the nitriding effect were obtained with RE addition. The most promising results were produced when RE-metals were added to the cathode of the plasma system. In PI3 nitriding, the relatively small improvement in nitriding kinetics, obtained using solid RE additions, was reproduced across a number of treatments. However, in DCPN and ASPN, which are the two most attractive methods for industrial processing, it was not possible to repeat the improvement in treatment kinetics on a regular basis.
During the second two-year period, significant progress was made in understanding ASPN processing and its benefits over DCPN processing. By using OES plasma species analysis in combination with metallurgical results, a good understanding has been reached about the overall mechanism of nitrogen mass transfer from the plasma to the steel specimen surfaces. Based on this investigation, ASPN is now recognised as the state-of-the-art in industrial plasma thermochemical processing. In several specific cases, RE additions did produce a significant improvement in the nitriding result. However, despite exhaustive efforts (including almost two hundred separate experiments), it has not been possible to reproduce these results.
In PI3 nitriding, work from this project lead to the finding that sputtered material detected by OES is an accurate indicator of the level of nitrogen ion bombardment and therefore of the quality of a particular treatment. Indeed, as a result of the findings from this study, OES is now regularly used to monitor PI3 processing in-situ. The four main results are:
- A series of interdisciplinary technical papers covering rare earth alloying and plasma processing.
- The first in-depth evaluation of Novel Active Screen Plasma Processing Technology.
- The realisation that plasma nitriding of rare earth containing low alloy steels can increase the effective case depth between 25-30% over the processing time range 5-10hrs. This has important energy and efficiency implications for the nitriding of steel.
- The identification of Optical Emission Spectrometry (OES) as a non-destructive quality control technique for Plasma Immersion Ion Implantation.
Searching for OpenAIRE data...
There was an error trying to search data from OpenAIRE
No results available